<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <script>
    // let user = prompt('请输入用户名')
    // let pwd = prompt('请输入密码')
    // if (user === 'admin' && pwd === '123456') {
    //   alert('登录成功')
    // }
    // else {
    //   alert('登录失败')
    // }
    let year = prompt('请输入年份')
    if (year % 4 === 0 && year % 100 !== 0 || year % 400 === 0) {
      alert('闰年')
    }
    else {
      alert('平年')
    }
  </script>
</body>

</html>